1. Field
One embodiment of the present invention relates to a communication system, a server apparatus, and a display control method which links data communication connection processing among data terminals, such as personal computers, to call connection processing.
2. Description of the Related Art
A private branch network system is used in an office and a business establishment. The private branch network system accommodates, for example, telephone sets in a telephone exchange apparatus, such as a private branch exchange (PBX) and a key telephone apparatus, as extension terminals, and exchange-connects among the extension terminals and an external communication network, such as a public network, and among the extension terminals with one another by means of the telephone exchange to enable telephone calls.
Recently, a system, which connects a server with data terminals, such as video phone terminals and personal computers, connected thereto to the telephone exchange via a transmission path, and links a voice communication system using the telephone exchange and a data communication system using the server, also has been proposed.
By the way, in the given parallel type system of the telephone exchange and the server, to construct a video conference, etc., the use of a multi-point control unit (MCU) is a possible approach (for instance, JP-A 7-264570 (KOKAI)).
However, the system does not apply the MCU to a visual communication system (VCS) which links data communication connections among the data terminals to call states of the telephone terminals.
In the case of the use of the MCU (hereinafter, referred to as MCU type), configuring a conference with few persons the use frequency of which is high frequently poses to be in short of conference resources of the MCU.
A method of connecting among data terminals by a VCS server itself in a mesh (hereinafter, referred to mesh type) being a possible approach, it is needed to treat a plurality of streams by the data terminals and it results in high load, as the number of speakers increases.
Furthermore, a method of switching between the MCU type and the mesh type in response to the number of speakers is also a possible one; however, the MCU type is a common window display system to synthesize a plurality of screens of conference members by the MCU, and an individual window display system is an individual window display system to individually display each screen of the conference members, so that the users that are the conference members feel something is wrong because the display system are also switched at every time when the MCU type and the mesh type are switched to each other.